<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>xxx</title>
    <script type="text/javascript" src="../js/jquery.min.js"></script>
    <script type="text/javascript" src="demo1.js"></script>
</head>
<body>
<canvas id="demo" width="400" height="400" style="background:#000">

</canvas>
</body>
</html>